The purpose of this study is to investigate that Cybernetics hypothesis of Systemic Theory can be applied to interpersonal system. Cybernetics hypothesis deals with about the self-regulatory function. That is, when the centrifugal tendency (centripetal tendency) affects system, interpersonal-communication changes centripetal tendency (centrifugal tendency). In this paper, The hypothesis was confirmed by several experimental studies.

　　Subjects were thirteen couples, members of the social dencing club in T University. Each couple was asked to discuss about three sorts of conflicting topics. Centripetal tendency was made by partition situation in which the couple can't see each other, Because disturbing interaction makes interpersonal system centripetally in conflict situation. Centrifugal tendency were made by forbiding smiling face. Because smiling face have centripetal tendency in conflicting situation. And control conflicting situation was carried out. Each utterance was classified into two linguistic strategies (the cooperation strategy, the confrontation strategy).

　　As a result, the confrontation strategy is higher at the partition situation than the control situation. And the cooperation strategy is higher at the forbiding smiling face situation than the control situtation.

　　In this study, self-regulatory function of inter-personal system was confirmed. Finally, it is suggested to be able to estimate changes of the system by paying attention to the self-regulatory function of inter-personal system.